Hox in frogs: xenopus reveals novel functions for vertebrate Hox genes

Hox genes are a very important family of transcription factors during development of vertebrate and invertebrates. This family of genes contains up to 39 Hox gene members organized in 4 clusters in the genome. The main function of Hox genes is the establishment of the anteroposterior axis of the embryo. During gastrulation of the frog Xenopus laevis, Hox genes start to be expressed in the mesoderm excluding the Spemann organizer mesoderm. However, a necessary interaction between the involuting mesodermal cells and the signals from the Spemann organizer center freeze the pattern of Hox expression at that time point. Thus a temporal Hox expression is converted into a spatial Hox expression during development. Moreover, Hox gene expression within the mesoderm seems to be important for Hox expression within the neural tissue. We missexpressed several Hox genes and analyzed their phenotype within the hindbrain and more posterior neural tissue. Paralogous 1 group Hox genes are important for globally pattern the hindbrain, while Hoxc6 gene seems to very important during neurogenesis in Xenopus. Axis elongation and segmentation are liked processes during development. We showed that Hoxc6 is an important gene for proper segmentation of Xenopus embryo.